Wood posts cannot be set directly on concrete because, in time, water will get on the concrete floor and cycles of wet and dry will rot the wood post. It is essential therefor to elevate the lower end of the wood post above the concrete floor. Preferably, the wood post should be attached to the concrete floor or foundation so that it will not be dislocated horizontally. Where the structure is subject to earthquake or high wind loads, the post should also be attached to the floor to prevent the post from moving upwardly. Because of the difficulty in setting post anchors to an exact height above the concrete surface and then cutting posts to an exact length, several attempts have been made to provide for adjustment of the height of the post anchor after the concrete has set. All of the prior art systems have proven to be either too expensive to construct or too expensive to install.
Jacking systems as taught by Holzbach U.S. Pat. No. 3,027,140 and Lear U.S. Pat. No. 3,831,329 are far too expensive. In housing projects where thousands of adjustable members might be used, even a few extra metal pieces or one or two welds can prove to be too expensive to contractors who are attempting to carefully cost out a project. Even when a do it yourselfer is building a single car port, an expensive jack would prove to expensive to the home owner who must be extremely careful in the expenditure of funds.
Machined and welded support members as taught by British Patent 1,260,281 granted to Robinson and U.S. Pat. No. 4,614,070 granted to Idland are far too expensive to compete in today's competitive markets.